A comparative study of the effect of intrathecal tramadol and buprenorphine used as adjuvants to hyperbaric bupivacaine for postoperative analgesia in infraumbilical surgeries

Abstract

Background & Objective: The augmentation of local anesthetics with various adjuvants to enhance the quality and efficacy of subarachnoid block is clinically in practice since long. Comparative studies on effects of adding intrathecal tramadol and buprenorphine has never been studied before. Both drygs are esily available in our country. So, we conducted this study to evaluate and compare the characteristics of subarachnoid blockade, duration of postoperative analgesia, dose of recue analgesic postoperatively, and adverse effects of intrathecal buprenorphine (50 μg) and intrathecal tramadol (30 mg) as adjuvants to 0.5% hyperbaric bupivacaine for lower abdominal surgeries Methodology: This prospective randomized, single blind controlled trial was carried out at Services Hospital Lahore, from January to July 2018. 110 American society of Anesthesiologist I II male patients, 35 to 45 y of age undergoing subarachnoid block for infra-umbilical surgery were randomized into two groups. Group T (n = 55) patients received 10 mg of 0.5% bupivacaine and 30 mg of tramadol intrathecally, while group B (n = 55) received 10 mg 0.5% bupivacaine with 50 μg of buprenorphine. Sensory testing was done by pin prick method using 25G blunt needle and time taken to reach T10 level noted. Motor block was assessed using Modified Bromage Scale. The time taken to reach modified Bromage 3 was recorded. Side effects and postoperative analgesia noted for 24 h by VAS score every 20 min for first 2 h in PACU and then 4 hourly for 24 h in the ward. Patients with inadequate block were converted into general anesthesia and were excluded from the study. Time to first rescue analgesia, and total analgesic required in 24 h were compared in two groups. Results: Mean VAS scores were less in Group T as compared to Group B. Significant difference was seen among groups at 45 min (p = 0.04), 60 min (p = 0.02), 75 min (p = 0.03), 90 min (p = 0.01), 120 min (p = 0.00), 4h (p = 0.007), 8 h (p = 0.01), 12 h (p = 0.01), 16 h (p = 0.00). After 24 h no significant difference was seen in both groups. Mean onset time for sensory block was earlier in Group B (2.4 min) compared to Group T (2.7 min)(p = 0.001). Mean onset time for motor block was earlier in Group B (4.8 min) as compared to Group T (5.5 min)(p = 0.00). No significant difference was seen among groups in side effects (p > 0.05). Mean time for rescue analgesia in Group B was earlier (4.51 ± 2.8 h.) as compared to Group T (4.94 ± 4.1h). Total dose of analgesic given in 24 h was significantly less in group T. (p = 0.004) The mean dose given in Group B (1.24 ± 0.96 mg/kg) was greater than Group T (0.76 ± 0.71 mg/kg) Conclusion: We conclude that both tramadol and buprenorphine, prolong the duration of postop analgesia without adding any adverse effects, but duration with tramadol is longer; it significantly reduces VAS and the dose of analgesic requirement in 24 h postoperatively. 4 ST: tramadol vs. buprenorphine as adjuvants to intrathecal bupivacaine